Systems that utilize a coil typically include circuits to protect the system from damage that could arise as the coil is charged and discharged. For example, overheating could result if a coil is charged and operated at a high current over a period that is too long. In another example, a kickback (i.e., flyback) voltage (e.g., voltage spike) could lead to an unwanted voltage breakdown (e.g., spark) if a coil is discharged over a period that is too short. Accordingly, new circuits and methods are needed to control a current in a coil.